1 Open your server control panel
2 In the “Security” section, select “Free SSL”
3 Select the desired domain in the list and click Release:
4 In the window that opens, select the subdomains that will be covered by the certificate.
5 Select a certificate activation method and click Issue:
6 You can check the correct installation of the certificate in the “Security” - “Free SSL” section in the list of your domains with an installed certificate from Let's Encrypt.
7 Done. You have installed the Let's Encrypt extension in cPanel.